Second checkpoint

internal/transport/http/category_handler.go

@@ -0,0 +1,173 @@
+package http
+
+import (
+	"net/http"
+	"strconv"
+
+	"gis/internal/service"
+	"gis/pkg/httputil"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-playground/validator/v10"
+	"github.com/google/uuid"
+)
+
+// CategoryHandler serves the /categories routes.
+type CategoryHandler struct {
+	svc      *service.CategoryService
+	validate *validator.Validate
+}
+
+// NewCategoryHandler returns a CategoryHandler.
+func NewCategoryHandler(svc *service.CategoryService, validate *validator.Validate) *CategoryHandler {
+	return &CategoryHandler{svc: svc, validate: validate}
+}
+
+// Register mounts the category routes on r.
+func (h *CategoryHandler) Register(r chi.Router) {
+	r.Get("/", h.list)
+	r.Post("/", h.create)
+	r.Get("/{id}", h.get)
+	r.Put("/{id}", h.update)
+	r.Delete("/{id}", h.delete)
+}
+
+type categoryRequest struct {
+	ParentID    *string `json:"parent_id" validate:"omitempty,uuid"`
+	Name        string  `json:"name" validate:"required,max=255"`
+	Description string  `json:"description" validate:"max=2000"`
+}
+
+func (r categoryRequest) toInput() (service.CategoryInput, error) {
+	in := service.CategoryInput{Name: r.Name, Description: r.Description}
+	if r.ParentID != nil {
+		id, err := uuid.Parse(*r.ParentID)
+		if err != nil {
+			return in, err
+		}
+		in.ParentID = &id
+	}
+	return in, nil
+}
+
+func (h *CategoryHandler) create(w http.ResponseWriter, r *http.Request) {
+	req, err := httputil.DecodeJSON[categoryRequest](w, r)
+	if err != nil {
+		httputil.WriteError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	if err := h.validate.Struct(req); err != nil {
+		httputil.WriteValidationErrors(w, err)
+		return
+	}
+	in, _ := req.toInput()
+
+	category, err := h.svc.Create(r.Context(), in)
+	if err != nil {
+		respondDomainError(w, err)
+		return
+	}
+	httputil.WriteJSON(w, http.StatusCreated, category)
+}
+
+func (h *CategoryHandler) list(w http.ResponseWriter, r *http.Request) {
+	parentID, ok := parseOptionalUUIDQuery(w, r, "parent_id")
+	if !ok {
+		return
+	}
+	categories, err := h.svc.List(r.Context(), parentID)
+	if err != nil {
+		respondDomainError(w, err)
+		return
+	}
+	httputil.WriteJSON(w, http.StatusOK, categories)
+}
+
+func (h *CategoryHandler) get(w http.ResponseWriter, r *http.Request) {
+	id, ok := parseUUIDParam(w, r, "id")
+	if !ok {
+		return
+	}
+	category, err := h.svc.Get(r.Context(), id)
+	if err != nil {
+		respondDomainError(w, err)
+		return
+	}
+	httputil.WriteJSON(w, http.StatusOK, category)
+}
+
+func (h *CategoryHandler) update(w http.ResponseWriter, r *http.Request) {
+	id, ok := parseUUIDParam(w, r, "id")
+	if !ok {
+		return
+	}
+	req, err := httputil.DecodeJSON[categoryRequest](w, r)
+	if err != nil {
+		httputil.WriteError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+	if err := h.validate.Struct(req); err != nil {
+		httputil.WriteValidationErrors(w, err)
+		return
+	}
+	in, _ := req.toInput()
+
+	category, err := h.svc.Update(r.Context(), id, in)
+	if err != nil {
+		respondDomainError(w, err)
+		return
+	}
+	httputil.WriteJSON(w, http.StatusOK, category)
+}
+
+func (h *CategoryHandler) delete(w http.ResponseWriter, r *http.Request) {
+	id, ok := parseUUIDParam(w, r, "id")
+	if !ok {
+		return
+	}
+	if err := h.svc.Delete(r.Context(), id); err != nil {
+		respondDomainError(w, err)
+		return
+	}
+	w.WriteHeader(http.StatusNoContent)
+}
+
+// parseUUIDParam reads a UUID path parameter, writing a 400 if it is invalid.
+func parseUUIDParam(w http.ResponseWriter, r *http.Request, name string) (uuid.UUID, bool) {
+	id, err := uuid.Parse(chi.URLParam(r, name))
+	if err != nil {
+		httputil.WriteError(w, http.StatusBadRequest, "invalid "+name)
+		return uuid.Nil, false
+	}
+	return id, true
+}
+
+// parsePositiveIntQuery reads an optional positive integer query parameter,
+// returning def when absent. A present but invalid value writes a 400.
+func parsePositiveIntQuery(w http.ResponseWriter, r *http.Request, name string, def int) (int, bool) {
+	raw := r.URL.Query().Get(name)
+	if raw == "" {
+		return def, true
+	}
+	v, err := strconv.Atoi(raw)
+	if err != nil || v < 1 {
+		httputil.WriteError(w, http.StatusBadRequest, "invalid "+name)
+		return 0, false
+	}
+	return v, true
+}
+
+// parseOptionalUUIDQuery reads an optional UUID query parameter. A missing value
+// yields (nil, true); an invalid value writes a 400 and yields (nil, false).
+func parseOptionalUUIDQuery(w http.ResponseWriter, r *http.Request, name string) (*uuid.UUID, bool) {
+	raw := r.URL.Query().Get(name)
+	if raw == "" {
+		return nil, true
+	}
+	id, err := uuid.Parse(raw)
+	if err != nil {
+		httputil.WriteError(w, http.StatusBadRequest, "invalid "+name)
+		return nil, false
+	}
+	return &id, true
+}